Impact of <i>Saccharomyces cerevisiae</i> Strain Selection on Malolactic Fermentation by <i>Lactobacillus plantarum</i> and <i>Oenococcus oeni</i>
Vasileios Englezos, Fabrizio Torchio, Paola Vagnoli, Sibylle Krieger-Weber, Kalliopi Rantsiou, Luca Cocolin
Abstract
Simultaneous inoculation of yeast and lactic acid bacteria (LAB) is considered a state-of-the-art strategy to reduce overall vinification time and improve microbiological stability of wines. This inoculation protocol sparked interest in selecting yeast and LAB strains to modulate malic acid consumption rate and wine composition. The study presented here addresses the impact on malic acid consumption and metabolite production of combining <i>Saccharomyces cerevisiae</i> strains with different fermentation rates and nutrition demands with <i>Lactobacillus plantarum</i> and <i>Oenococcus oeni</i> strains. <i>S. cerevisiae</i> strains in pure culture fermentations without LAB inoculation exhibited different patterns of malic acid consumption rate and metabolite production. Simultaneous <i>S. cerevisiae</i> and LAB inoculation influenced the kinetics of lactic acid production and titratable acidity in a LAB-strain dependent manner. Wines undergoing malolactic fermentation with <i>L. plantarum</i> ML Prime finished faster and contained more L-lactic acid than similar wines inoculated with <i>O. oeni</i> Lalvin VP41; however, the degree of acidification depended on the <i>S. cerevisiae</i> strain used to conduct alcoholic fermentation. This study reveals new knowledge about the use of <i>L. plantarum</i> in winemaking and shows the effect of <i>S. cerevisiae</i> strains with different enological characteristics, with or without LAB co-inoculation, on wine composition.